Photochromism of new isomeric pyridine-containing diarylethenes with a benzofuran moiety

• Three isomeric pyridine-containing diarylethenes were synthesized.
• They exhibited multi-addressable switching behavior by light and acid/base stimuli.
• The effect of nitrogen atom position in pyridine unit on photochromism was discussed.

Three new isomeric pyridine-containing diarylethenes with a benzofuran moiety were synthesized, and the structures of two diarylethenes were determined by single X-ray diffraction analysis. Their properties such as photochromism, acidchromism, fluorescence, as well as electrochemical properties, were investigated in detailed. The diarylethenes exhibited multi-addressable switching behavior by light and acid/base stimuli in solution and functioned as a remarkable fluorescent switch in both solution and poly(methyl methacrylate) films. Among these isomeric derivatives, the example with the nitrogen atom at the ortho-position of pyridine showed the largest absorption maxima, molar absorption coefficients, and cyclization quantum yield. The nitrogen atom position in the terminal pyridine unit could efficiently modulate the optical and electrochemical properties of the diarylethenes with a benzofuran moiety. The results suggested that the benzofuran moiety and the nitrogen atom position in the terminal pyridine unit played a vital role during the process of photoisomerization reaction for these isomeric diarylethenes.

A new class of isomeric diarylethenes with a benzofuran moiety was synthesized and their multi-addressable switching behaviors induced by light and acid/base were discussed in detail. Figure optionsDownload as PowerPoint slide